1. Field of the Invention
The present invention relates to an imaging system in which a lens surface projects from a housing.
2. Description of the Related Art
An imaging system using a plurality of wide-angle lenses such as a fisheye lens or a super-wide-angle lens is known as an imaging system which images all directions at one time. In such an imaging system, an image from each lens is projected on the same or corresponding sensor, and the projected images are combined by an image process, so as to produce an omnidirectional image.
When an imaging system is created with a small number of optical components, an angle of view assigned to each lens tends to be increased. For example, when photographing an omnidirectional image by using two fisheye lenses, each of the fisheye lenses requires a 180° or more angle of view.
A wide-angle lens, however, tends to have a small curvature radius on the incident side, and project from a housing. In an imaging system in which a lens surface projects from a housing, a lens is easily damaged when dropping the imaging system.
A technique described in Patent Document 1 (JP S62-191838A), for example, is known as a technique which protects a lens from being damaged. Patent Document 1 discloses a camera with a lens cover in which a push button for opening and closing a lens cover is provided in a side face of a lens barrel cover on a grip side. Such a technique described in Patent Document 1 requires the push button for opening and closing a lens cover, resulting in an increase in costs.
In the above-described imaging systems, in particular, an imaging system having a linear housing, an optical system, shutter button, and power supplier are often linearly arranged. A photographer holds such an imaging system between the gravity center of the imaging system and the position of the shutter button. When the arrangement of an optical system and a power supplier, which account for a substantial fraction of the weight of the imaging system, is inappropriate, camera shake easily occurs in the case of pushing the shutter button. It therefore becomes difficult for a photographer to stably perform photographing.